Apodrosus Marshall, 1922 : 59

Girón, Jennifer C. & Franz, Nico M., 2010, Revision, phylogeny and historical biogeography of the genus Apodrosus Marshall, 1922 (Coleoptera: Curculionidae: Entiminae), Insect Systematics & Evolution 41, pp. 339-414 : 342-353

publication ID	https://doi.org/ 10.1163/187631210X538799
DOI	https://doi.org/10.5281/zenodo.3803628
persistent identifier	https://treatment.plazi.org/id/03807F35-FFA9-FF93-AF5B-EE03FBA4FF40
treatment provided by	Plazi
scientific name	Apodrosus Marshall, 1922 : 59
status

Treatment

Apodrosus Marshall, 1922: 59 View in CoL

= Apodrusus Marshall (in Wolcott 1924: 130 – error)

Type species

Apodrosus wolcotti Marshall 1922: 59 View in CoL , by original designation.

Diagnosis

Apodrosus is a genus of relatively small sized (3-7 mm), often metallic colored, exclusively (western) Caribbean entimine weevils with phanerognathous mouthparts (i.e., the maxillae are visible along the sides of the prementum; Fig. 2A View Fig ), without a postocular lobe and vibrissae, and with the humeri and wings being well developed. Species of Apodrosus may resemble those of members of the Anypotactini and Polydrusini . According to Marshall (1922: 59), the genus shares with the strictly continental Polydrusus “its more salient characteristics”, including a laterally situated antennal scrobe and connate claws(see also Anderson 2002).However, Apodrosus can be distinguished from Polydrusus and other polydrusine genera by a particular combination of characters including a median furrow on the head (e.g., Fig. 8B View Fig ); a large, bare, and smooth triangular area formed by the epistome on the rostrum (e.g., Fig. 1B View Fig ); the presence of premucro; the presence of a median fovea on the ventral sternum VII; and an either J- or Y-shaped female spermatheca (e.g., Figs 5 View Fig Dand 13G). Apodrosus is furthermore distinguished from an undescribed though apparently closely related genus that also occurs at higher elevations in the Hispaniolan Cordillera by having a well defined epistome, well developed elytral humeri, and fully developed wings (pers. obs.). Finally, Apodrosus differs from Anypotactus Schoenherr in having connate (as opposed to free) claws.

Redescription

Body. Length 2–6 mm; length in dorsal view 2–3-times longer than greatest width which is either at humeri or at mid-point to second third of elytra (e.g., Fig. 1A View Fig ); shape usually subrectangular; dorsal outline in lateral view subplane to strongly convex (e.g., Fig. 1C View Fig ). Integument dark brown, paler or more reddish or yellowish on legs, lighter in teneral specimens; surface smooth to undulated; vestiture heterogeneous to uniform, composed of small, circular to elongate, appressed, contiguous, mostly nonoverlapping (excepting lateral and apical regions of elytra), white to brown or green, iridescent (yellowish, reddish or greenish), with ribbed surface scales, and short and recurvate or long and erect setae, regularly and sparsely arranged throughout.

Head. Shape in dorsal view subconical (e.g., Fig. 1B View Fig ). Eyes in dorsal view slightly to strongly projected from the surface of the head (e.g., Figs 10 View Fig Band 11B), inner margins converging apically; in lateral view elliptical, 1.4–1.9-times longer than wide; eyes 0.3–0.6-times width and 0.6–0.8-times length of head in lateral view; separated from anterior margin of prothorax by 0.3–0.7-times greatest diameter of eye; ocular sclerite well defined all around the eye; imaginary line of anterior margin of eyes usually impressed. Frons trapezoidal (e.g., Fig. 13B View Fig ), shortest distance between eyes 0.2–0.5- times greatest width of pronotum; with a mesal longitudinal furrow of variable length and depth, furrow apically linear or bifurcated. Rostrum in dorsal view nearly as long as head, 1–1.5-times longer than wide, lateral margins parallel (or converging towards apex or mesally slightly emarginate – rostrum mesally constricted –); median region of rostrum flat to slightly produced; epistomal area well defined (e.g., Fig. 2B View Fig ), large, triangular, glabrous and shiny, usually extending to antennal insertion, apically with 3–5 setae situated on each side; nasal plate (on the apical margin of epistome) not always defined, if so, then flat to concave, finely puncturate, variable in size. Rostrum in lateral view slightly curved downwards, length 1–1.6-times its basal width; antennal insertion apicad of mid length of rostrum; scrobe curved downwards by 40–70°, well defined throughout, deep, glabrous, initiating in apicodorsal region, ending in basiventral region, posteriorly or ventrally directed, extending at least to anterior margin or at most to anterior third of eye, separated from it (at shortest distance) by 1.2–2.7-times width of scrobe; ventral surface ( Fig. 2A View Fig ) with scarce long suberect setae; gular suture clearly visible, with a shallow basal pit, continuing as shallow to deep lateral subgenal sutures with anterior and posterior pits clearly defined.

Mouthparts. Mandibles glabrous and shiny; each mandible with 1–2 long, laterally positioned setae, with pharyngeal process 0.9–1.6-times length of mandible; mandibular scar ( Fig. 2A View Fig ) (strongly) reduced, not always clearly visible, apicoventrally situated; deciduous process ( Fig. 2B View Fig ), if present, short and sickle-shaped. Maxillae ( Fig. 2A and 2C View Fig ) visible along the sides of the prementum, with cardo slender, 3–4-times longer than its greatest width, apically widened, roundly and strongly curved at junction with stipes; stipes with 1–4 lateral setae; palpiger usually with one long lateral seta, surface covered with short, sparse setae, fused with galeo-lacinial complex; the latter mesally extending (at least) to apex of maxillary palpomere I or (at most) to midpoint of maxillary palpomere III; galea apically widely rounded, usually with 4–8 tongue-like apically narrowed setae at apex and often with a basal tuft of shorter, narrower, apically rounded setae; lacinia with 3–5 lacinial teeth and two to several or many long fine setae at base; maxillary palps 3-segmented, maxillary palpomeres of variable lengths, I and II usually with 1–2 mesal lateral setae; apex of palpomere III with papillae. Labium ( Fig. 2 View Fig Aand 2D) with prementum not covering the maxillae; prementum subquadrate to rectangular, 1.1–1.9-times longer than wide, with external surface smooth or reticulate; labial palps 3-segmented, inserted near the apex of prementum; palpomeres often apically gradually reducing in size; frequently labial palpomere I with 1 long lateral or ventral seta, III with papillae; postmentum projected as a peduncle.

Antennae. 12-segmented, reddish to yellowish, light brown; antennal scape slender, apically widened, extending (in repose) to second third of eyes up to beyond posterior margin of eyes, though not reaching anterior margin of prothorax, passing far below eye, with scarce and sparse fine setae, almost glabrous; funicle 7-segmented, often as long as scape; funicular antennomere I apically widened, usually longer and thicker than II; II usually cylindrical, longer than remaining antennomeres; funicular antennomeres III–VII clavate, progressing from elongate to equilateral, similar in shape and length; antennal club 4-segmented, finely and densely pilose, 0.5–0.8-times length of funicle, 2–3-times longer than wide; club segments I and IV usually similar in length, II and III each slightly longer.

Thorax. Pronotum transverse to cylindrical (e.g., Figs 1 View Fig Aand 6A), greatest width at apical third or at midpoint; dorsal surface usually smooth (in some species slightly transversally impressed at anterior third), shallowly and sparsely puncturate, each puncture with a seta; lateral margins subparallel, slightly rounded near midpoint; posterior margin straight to bisinuate, 1–1.3-times width of anterior margin; prothorax in lateral view cylindrical, dorsal outline usually straight, 1.3–1.6-times longer than ventral outline, with anterior margin straight, postocular setae absent; scutellum conspicuous, variously shaped, shiny, usually with scarce setae, almost glabrous. Prosternum and metasternum nearly the same length (e.g., Fig. 1D View Fig ), mesosternum 0.5–0.9-times length of prosternum and strongly inflected in relation to pro- and metasternum (e.g., Fig. 1D View Fig ); procoxal cavities contiguous, positioned slightly closer to anterior than to posterior margin of prosternum. Mesosternum with mesocoxal cavities each 3–5-times wider than intercoxal process. Mesepimeron and mesepisternum triangular, suture separating them foveate ventrad of midpoint. Metasternum with a median posterior fovea either well developed or reduced, each lateral portion mesally and posteriorly produced (in lateral view, metasternum gradually produced posteriorly), usually each terminating abruptly as a horizontal plica; distance between posterior margin of mesocoxae and anterior margin of metacoxae 0.6–0.9-times length of prosternum; distance separating metacoxal cavities 0.5–0.6-times width of each metacoxal cavity. Metendosternite ( Fig. 3A View Fig ) with furcal arms longer than stalk, positioned nearly at 120° (or 60°) in relation to horizontal axis (=imaginary straight line connecting hemiducts); ventral margin of stalk 1.3–3.6-times its dorsal width; anterior tendons inserted at midpoint or slightly closer to midline than to base of furcal arms.

Legs. Uniformly and densely covered with scales, except on posterior surface of metafemora; femora unarmed, 1.0–1.5-times length of pronotum, mesofemur slightly shorter; tibiae straight, slightly curved inwards at apical 1/6, without denticles, usually with spiniform setae on ventral margin; mucro shorter than tarsal claws, premucro present; apex of protibiae with anterior margin usually straight, with an apical fringe of whitish, yellowish or brownish, stout setae; mesotibiae slightly shorter, with anterior margin dorsally oblique, with an apical fringe of fine, spiniform setae, setae increasing in length towards dorsal margin; metatibiae with anterior margin dorsally oblique, with an apical fringe of yellowish or brownish, fine, spiniform setae, setae increasing in length towards dorsal margin, and with a flange shielding tarsal insertion outwardly (corbel semi-enclosed); surface surrounding tarsal condyle glabrous and shiny; tarsi ventrally densely covered with setae, with tarsomeres I and II subtriangular, I slightly longer than II, III bilobed, 2-times wider than II, IV short, 0.2-times width of II, V shorter than I+II combined; claws connate, simple, subparallel.

Elytra (e.g., Figs 1 View Fig Aand 6A).Length in dorsal view 1.1–2-times their greatest width, which is 1.5–1.9-times wider than pronotum; anterior margins straight to sinuate; humeri present, roundly angulate; humeral region 1.5–1.6-times width of posterior margin of pronotum; lateral margins usually parallel, divergent on basal two-thirds, then straightly to roundly converging to apex; apex widely to narrowly rounded; in lateral view with dorsal outline subplane to strongly convex; posterior declivity gradual, widely rounded to nearly straight; with 10 complete elytral striae, separated from each other by a distance similar to width of a metatibia; punctures deep and glabrous, separated from each other longitudinally by distance similar to the length of each puncture; striae IX and X either completely separated along their entire length by a more or less uniform distance, or fused in mid region along the second third of elytra; intervals uniformly covered with scales, sometimes forming different color patterns, with recurvate and decumbent or straight and erect setae regularly arranged in rows along mid region of elytral intervals; interval X flat to produced along second fifth or sixth of elytra.

Wings ( Fig. 3B View Fig ).Fully developed, 1.2–2.5-times length of elytra, 3–3.7-times longer than wide; costal margin from nearly straight to emarginate along basal half and slightly rounded thereafter; apex widely to acutely rounded, usually as wide as base (distad of alar sclerites); alar venation usually well developed: R and Rr well defined and rs distinct, darkened; radial window (W) defined; R3 weakly defined, not reaching alar margin; pst distally narrowed, not reaching alar margin; mst weakly defined; h conspicuous, not reaching alar margin; radial and medial margins nearly straight; Mr, Cu and Cu 1 well defined, af distinct; cubital margin nearly straight; 1A 1 and 1A 2 slightly visible near margin; 2A well defined, vanishing at margin; 3A usually short, at most reaching mid length towards margin of wing, intersecting or not with 2A; 4A visible as a vanishing light stripe; anal area with margin usually rounded; medial, cubital and anal margins with a fringe of short and fine setae separated from each other by distance similar to the length of a seta.

Abdomen. Venter (e.g., Fig. 1D View Fig ) scarcely to densely covered with scales; segments V–VII separate; posterior margin of IV slightly rounded in mid region; VII with anterior margin 1.9–2.5-times wider than its length, usually with a median posterior fovea; ♂: posterior margin of III mesally slightly acutely emarginate, IV 1.2–2-times longer than V to VI jointly, IV 1-1.4x length of VII, posterior margin of VII widely rounded; ♀: posterior margin of III mesally roundly emarginate, IV usually longer than in males, IV 1.4–2-times length of VII, VII posterior margin rounded, slightly narrower than in males.

Terminalia. Male with tergum VII ( Fig. 4A View Fig ) transverse to slightly elongate, with two meso-lateral, longitudinally aligned, transversely strigulate stripes extending to posterior margin, continuing laterally into an area with fine, appressed spines, mesal area basally wider than a strigulate stripe, posteriorly widened, with simple or multifid setae particularly concentrated in posterior area; anterior margin of tergum VII rounded to triangular; posterior margin laterally rounded, mesally emarginate to rounded. Tergum VIII ( Fig. 4B View Fig ) transverse to equilateral, with anterior margin rounded to mesally acutely emarginate; surface usually evenly convex; posteriorly coarsely puncturate, with setae; posterior margin from slightly emarginate in mid region and laterally widely rounded to widely rounded. Sternum VIII ( Fig. 4C View Fig ) forming an entire sickle-shaped plate, usually with spiculum relictum forming a forked process. Sternum IX (spiculum gastrale) ( Fig. 4D View Fig ) with apodeme 1.1–1.6-times longer than aedeagus, anteriorly expanded into an asymmetrical, irregular lamina, posteriorly rounded, narrowly truncate; furcal arms opposed, semi-oval to triangular, variable in degree of sclerotization, separated from stylus yet connected to it by a membrane. Tegmen ( Fig. 4E View Fig ) with tegminal apodeme 0.6–1-times length of aedeagus; basal piece fused with tegminal plate forming a simple ring; tegminal plate simple or mesally slightly projected posteriorly. Aedeagus in dorsal view ( Fig. 4F View Fig ) 3.3–5-times longer than its greatest width, parallel sided to mesally narrowed or apically slightly widened; apex variable. Endophallus with at least a pair of variously shaped, opposed and sclerotized areas positioned near apex, closing the ostium, and 1–2 single or paired sclerites near midpoint; usually without teeth, if present, accommodated in usually a pair of rows of few (3–6) and stepwise alternating or many and contiguous, directed to median longitudinal axis of aedeagus. Aedeagus in lateral view ( Fig. 4G View Fig ) dorsally convex, length 7–10-times its greatest width; dorsal and ventral outlines not uniformly curved, convergent basally. Aedeagal apodemes 0.8–1.1-times length of aedeagus, anteriorly widened; curved at some point, thereafter nearly straight towards base of aedeagus.

Female. With tergum VII transverse to slightly elongate, without strigulate stripes; lateral areas with fine, appressed spines; anterior margin rounded; posterior margin mesally emarginate to rounded; marginal area coarsely puncturate, with simple or multifid setae in distal third. Tergum VIII subtriangular, transverse to elongate, anterior margin emarginate, apical margin usually rounded and apical area puncturate, with setae. Sternum VIII ( Fig. 5A View Fig ) slightly shorter than ventral sterna III–VII jointly, lamina occupying posterior one-fourth to one-fifth, triangular, sagittate, rhomboidal or semicircular, with rounded corners; usually median longitudinal region more sclerotized than basilateral sides, apicolateral areas upwardly plicate, apex with punctures and setae. Coxites+styli ( Fig. 5 View Fig Band 5C) 0.8–1.6-times length of lamina of sternum VIII, stylus 2.4–3.6-times longer than its greatest width, obovate, inserted apicodorsally, with 2–5 apical setae. Genital chamber 0.6–0.8-times length of sternum VIII. Spermatheca (e.g., Figs 5 View Fig Dand 13G) 1.2–1.8-times longer than wide, J- or Y-shaped; cornu nearly straight, length similar to greatest width of spermatheca, usually perpendicular to ramus, with an abruptly narrowed apical projection; margin between cornu and ramus nearly straight; ramus usually longer and wider than collum, apically truncate to rounded, separated from collum by a straight lateral margin; collum usually laterally produced above mid-length of corpus, generally apically narrowed, truncate; surface usually striate, particularly on cornu and ramus.

Etymology

Noun in apposition. Possibly named by Marshall (1922) to express a close affinity to Polydrusus , with the Greek term apo meaning “related to” and drosos meaning “dew, drop” (cf., Brown 1956) which may allude to the weevils’ body shape in dorsal view.

Key to the species of Apodrosus View in CoL

1. Posterior margin of epistome projected basad of rostrum as a carinate stripe; antennal scape surpassing posterior margin of eyes …………………..……2

1'. Posterior margin of epistome not projected; antennal scape usually not or merely reaching posterior margin of eyes………….……………….………6

2(1). Lateral profile of metasternum posteriorly strongly projected …….….……3

2'. Lateral profile of metasternum posteriorly only slightly produced; body narrow in dorsal view (3.2-times longer than wide); vestiture composed of yellowish brown, black and green, iridescent (yellowish, reddish) scales, with recurvate, lanceolate brown setae ( Fig. 6 View Fig )……….….…….…… A. artus View in CoL sp.n.

3(2). Surface of elytra produced basad of midpoint of interval X…….………….4

3'. Surface of elytra flat along interval X; in dorsal view shield-shaped; elytral striae IX and X fused along their second third; vestiture composed of brown, coppery and green, iridescent (greenish to yellowish) scales, with erect setae; apex of aedeagus uniformly rounded ( Fig. 7 View Fig ) …….…....…….…… A. andersoni View in CoL sp.n.

4(3). Surface of elytra strongly produced basad of midpoint of interval X; nasal plate indistinct…………………………………………………………….5

4'. Surface of elytra slightly produced along basal fourth of interval X; nasal plate visible; eyes strongly projected; vestiture composed of dark brown, light brown and green, iridescent (reddish) scales, with long, erect and apically truncate, brown and whitish setae ( Fig. 8 View Fig )…………… A. earinusparsus View in CoL sp.n.

5(4). Elytral striae IX and X completely separated along their entire length; scale coverage of legs with color pattern; dorsal outline in lateral view subplane to

convex; integument surface slightly tuberculate; vestiture composed of brown, light brown to white, iridescent (greenish, yellowish to reddish) scales, with recurvate, semi-erect setae ( Fig. 9 View Fig )….….….…………… A. epipolevatus View in CoL sp.n.

5'. Elytral striae IX and X fused along their second third; scale coverage of legs uniformly colored; dorsal outline in lateral view convex to strongly convex; integument surface slightly undulate; vestiture composed of dark brown, light brown to white, iridescent (reddish) scales, with recurvate, decumbent, brown setae ( Fig. 1 View Fig )…………………………………………… A. wolcotti Marshall View in CoL

6(1'). Antennal scape not or merely reaching posterior margin of eyes…….….….7

6'. Antennal scape surpassing posterior margin of eyes; eyes strongly projected; vestiture composed of gray and light green, iridescent (greenish to reddish) scales; apex of aedeagus uniformly endophallus ( Fig. 10 View Fig )…… A. eximius View in CoL sp.n.

7(6). Eyes in dorsal view large and flattened; elytral striae IX and X completely separated along their entire length; vestiture composed of white, light brown or silvery scales…………………………………………………………….8

7'. Eyes in dorsal view mid-sized and produced; elytral striae IX and X fused along their second third; vestiture composed of brown, white or green scales……….….………………………………………………………….9

8(7). Nasal plate indistinct; body length 3–5 mm; in dorsal view 2-times its greatest width which is at midpoint of elytra, shape subrectangular; aedeagus without denticulate pads on endophallus ( Fig. 11 View Fig )………….….… A. argentatus Wolcott View in CoL

8'. Nasal plate visible; body length 6 mm; in dorsal view, shield-shaped, 2.8x longer than its greatest width which is at anterior third of elytra; aedeagus with a pair of denticulate pads positioned apicad of midpoint of aedeagus ( Fig. 12 View Fig )…………………………………………….… A. mammuthus View in CoL sp.n.

9(7'). Median furrow of head apically bifurcated……………………….………10

9'. Median furrow of head reduced, linear; body length 2.5–3.5 mm; vestiture composed of green and pink (on legs), iridescent (reddish) scales, with straight, erect, yellowish setae ( Fig. 13 View Fig )…….…….………………… A. viridium View in CoL sp.n.

10(9). Rostrum mesally constricted; interval X of elytra slightly produced along second fifth………………………………………………………………… 11

10'. Rostrum without a mesal constriction; interval X of elytra flat; eyes narrow in lateral view; vestiture uniformly composed of green and white (on legs) iridescent (reddish) scales, with recurvate, decumbent, brown setae ( Fig. 14 View Fig ) …………………………………………….……….…… A. stenoculus View in CoL sp.n.

11(10). Legs coverage uniformly colored; cornu and ramus of spermatheca forming an acute angle of 40–60°…………………………………………………12

11'. Legs coverage not uniformly colored; vestiture composed of white and brown, iridescent (yellowish, reddish to greenish) scales, with recurvate, decumbent, yellowish setae; cornu and ramus of spermatheca forming an angle of nearly 90° ( Fig. 15 View Fig )………………………….……….……… A. quisqueyanus View in CoL sp.n.

12(11). Vestiture composed of white and light brown, iridescent (yellowish to reddish) scales; spermatheca with a constriction between cornu and corpus ( Fig. 16 View Fig )…………………………………………… A. empherefasciatus View in CoL sp.n.

12'. Vestiture uniformly composed of brown, iridescent (reddish) scales and white scales on the ventral surface; spermatheca not constricted between cornu and corpus ( Fig. 17 View Fig )………………………….….……………… A. adustus View in CoL sp.n.